<template>
  <div class="pagination">
      <button :disabled="pageNo==1" @click="$emit('getPageNo',pageNo-1)">上一页</button>
    <button v-if='startEnd.start>1' @click="$emit('getPageNo',1)" :class='{active:pageNo==1}'>1</button>
    <button v-if='startEnd.start>2'>···</button>
  
    <button v-for='(page,index) in startEnd.end' :key='index' v-show='page>=startEnd.start' @click="$emit('getPageNo',page)" :class='{active:pageNo==page}'>{{page}}</button>
    
    <button v-if='startEnd.end<totalPage-1'>···</button>
    <button v-if='startEnd.end<totalPage'  @click="$emit('getPageNo',totalPage)" :class='{active:pageNo==totalPage}'>{{totalPage}}</button>
    <button :disabled='pageNo==totalPage' @click="$emit('getPageNo',pageNo+1)">下一页</button>
    
    <button style="margin-left: 30px">共{{total}}条</button>
  </div>
</template>

<script>
  export default {
    name: "Pagination",
    props:['pageNo','pageSize','total','continues'],
    computed:{
        totalPage(){
            return Math.ceil(this.total/this.pageSize)
        },
        startEnd(){
            const {continues,totalPage,pageNo}=this
            let start=0,end=0;
           if(continues>totalPage){
               start=1
               end=totalPage
               
           }else{
               start=pageNo-parseInt(continues/2)
               end=pageNo+parseInt(continues/2)
               if(start<1){
                   start=1
                   end=continues
               }
               if(end>31){
                   start=totalPage-continues+1
                   end=totalPage
               }
           }
           return {start,end}
        },
    }
  }
</script>

<style lang="less" scoped>
  .pagination {
    text-align: center;
    button {
      margin: 0 5px;
      background-color: #f4f4f5;
      color: #606266;
      outline: none;
      border-radius: 2px;
      padding: 0 4px;
      vertical-align: top;
      display: inline-block;
      font-size: 13px;
      min-width: 35.5px;
      height: 28px;
      line-height: 28px;
      cursor: pointer;
      box-sizing: border-box;
      text-align: center;
      border: 0;

      &[disabled] {
        color: #c0c4cc;
        cursor: not-allowed;
      }

      &.active {
        cursor: not-allowed;
        background-color: #409eff;
        color: #fff;
      }
      .active{
        background-color: #409eff;
      }
    }
  }
</style>


